Does the multiple re-entry permit for an ED visa in Thailand extend my stay each time I travel?

As an exchange student on an ED single entry visa, a multiple re-entry permit allows you to leave the country and return without losing the status of your current visa. However, it does not restart the 90-day duration of your visa; it simply preserves your original 'Admitted until' date. To stay beyond your initial 90 days, you must apply for a visa extension.